System and method for manufacturing polymer coated controlled release fertilizers

ABSTRACT

A system and method are provided for manufacturing the polymer-coated fertilizers with a controlled release in a single pass. The system has a feeding mechanism connected to a first chill roll to supply the articles to the first cavities provided on the first roll to store and hold the articles. A first machine produces and applies a first polymer film on the articles held in the first chill roll to coat the articles partially with the first polymer film. The partially coated articles are transferred to a second chill roll placed at a side or on a top of the first chill roll. A second machine produces and applies the second polymer film on the partially coated articles in the second chill roll so that the articles are encapsulated by the first and second polymer films. A collector mechanism receives the encapsulated articles from the second chill roll.

CROSS REFERENCE TO RELATED APPLICATION

The present application is continuation-in-part of Ser. No. 14/421,59,filed Feb. 13, 2015. The content of the abovementioned document isincorporated entirely by reference herein.

BACKGROUND Technical Field

The embodiments herein generally relate to fertilizers and particularlyto polymer coated fertilizers. The embodiments herein more particularlyrelate to a system and method for manufacturing polymer-coatedfertilizers with a controlled release mechanism for plants and crops.

Description of the Related Art

A fertilizer is an organic or inorganic material of natural or syntheticorigin that is added to a soil to supply one or more plant nutrientsessential for the growth of the plants. Fertilizers are broadly dividedinto organic fertilizers (composed of plants or animal matters), orinorganic/commercial fertilizers. Plants absorb the required nutrientsonly when they are present in a form of easily dissolved chemicalcompounds. Both the organic and inorganic fertilizers provide the samechemical compounds that are needed. The organic fertilizers provide bothmacro and micro nutrients. The macro and micro nutrients are released asthe organic matter decay. The decay may take months or years. Furtherthe organic fertilizers have lower concentrations of plant nutrients andhave the usual problems of economical collection, treatment,transportation and distribution. Inorganic fertilizers are readilydissolved and applied to the soil. The dissolved inorganic fertilizersis readily taken by the plant roots.

Most of the commercially available fertilizers, when applied to thelawns or agricultural crops, dissolve rapidly in the moisture of thesoil. Often, such fertilizers dissolve at a rate that exceeds the ratein which it is absorbed by the plants. This causes a number ofsignificant problems. First, the excess fertilizer can leach into thegroundwater thereby generating a potentially serious environmentaldamage. In addition to the above, an excessive concentration of thefertilizers in the vicinity of a plant may result in a burning or damageof the plant roots. Because of these problems, it is often necessary toapply these fertilizers in several light doses throughout the growingseason, rather than in a single heavy application. However, the need forrepeated applications increases a cost of the labor. At worse, therepeated applications may cause a physical damage to the growing plantsbecause the fertilizer spreading equipment must pass over the plants forseveral times.

In order to minimize the loss of fertilizer into the environment and toavoid the need for the repeated applications, various slow or controlledrelease fertilizers have been developed. The U.S. Pat. Nos. 4,042,366,5,147,443, 5,435,821, and 6,231,633 disclose such controlled releasefertilizers. These fertilizers are applied at the beginning of thegrowing season to facilitate a higher release of fertilizer in theinitial growing period followed by a slower release or gradual releaseof fertilizer throughout the growing season. The slow or controlledrelease fertilizers are widely used on the agriculture crops, homelawns, public lawns, golf courses, home gardens, plant nurseries, andfor horticultural crops.

The polymer coated fertilizers are the most technically advancedcontrolled release fertilizers. Many manufacturing methods are developedand used to produce polymer-coated fertilizers and they are disclosed inthe U.S. Pat. Nos. 4,019,890, 4,369,055, 5,176,734, 5,211,985,5,374,292, 5,858,094, 6,338,746, and 8,211,201. The polymer coatedcontrolled release fertilizers are typically produced by coating a waterinsoluble semi-permeable polymer layer onto the fertilizer granules. Thefertilizer is released over a time period into the soil by diffusionthrough this semi-permeable coating.

One of the popular methods of manufacturing the polymer-coatedfertilizers is by reacting the chemical monomers onto the surface of thegranule to form a polymer film. This method is called a reactive layercoating in which a polyurethane polymer is formed. Another popularmethod of manufacturing the polymer coated fertilizers is by spraying asolution of polymer onto the fertilizer granules and evaporating thesolvent thereby forming a polymer film coating. This method is calledfluidized bed coating and it requires an expensive solvent and a solventrecovery system.

The most critical aspect of the controlled-release fertilizers is themoisture permeability of the coating, which is affected by the thicknessand the molecular structure of the coating. The release of fertilizertakes place via diffusion through the coating and the uniformity of therelease rate depends on the uniformity of the coating. An uneven coatingthickness will have uneven moisture transmission rate and hence thequality of the controlled-release products will also vary.

Another critical shortcoming of the existing coating technologies isthat these coating processes spray polymer solution onto a plurality offertilizer granules which are tumbling and rolling in a random fashioninside a rotary drum or in a vertical column of fluidized bed. Theuneven shaped granules produce completely random rolling pattern thusthe coating cannot be directed and this results into an uneven coatingthickness. This problem worsens when the shape is extremely uneven ornon-spherical such as the fertilizer products made by compactionprocess, which have highly uneven shape. Thus all existing coatingtechnologies require expensive premium grade round fertilizer granulewith smooth surfaces (U.S. Pat. No. 6,139,597 A) so that non-uniformityof the coating can be minimized.

The disadvantages suffered by the existing process are that either thesemethods are polymer specific such as polyurethane processes or theprocess requires an expensive solvent to produce the coating in case offluidized bed coating. All these methods produce the products that arevery expensive and sometimes the cost is equal to 4-6 times the pricesof the conventional fertilizers. The primary reason for the expensivenature is the use of expensive polymers or the use of an expensivesolvent or both. Yet another disadvantage is that most of thesemanufacturing processes are batch type processes, which are expensive.

Another disadvantage with the existing processes is that they requiremultiple applications of polymer to increase the thickness of thepolymer coating around the fertilizer, as disclosed in U.S. Pat. No.7,018,441 B2. For example, it requires nearly 16 applications of thepolyurethane polymer to achieve a coating thickness of 8%. A coatingthickness 0.5% only is achieved in each application and hence more timeand energy are required for multiple applications thereby increasing theproduction cost.

Yet another disadvantage of the existing coating technologies is thatthe fertilizer granules with lower compression or crushing strengthcannot be coated due to turbulence in the coating system.

A manufacturing process is disclosed in the U.S. Pat. No. 8,211,201 toovercome the above-mentioned disadvantages. But one disadvantage of thisprocess is the use of molten fertilizer as a feed to produce the coatedfertilizers thereby leaving a majority of fertilizer granuels includingfertilizers in tablet, spikes, pellet, or briquette form. The meltingand solidifying of the fertilizer granules requires a substantial amountof energy, which increase the production cost and many fertilizerscannot be produced in melt form for use in this process. Additionallythe process produces the coated products in hemispherical or pasttileshape which may not be appealing to many users.

Hence there is a need for an economical system and method formanufacturing polymer coated controlled release fertilizers continuouslyto enable the use any available fertilizer granule in any shape and formfor producing polymer coated products with uniform coating thickness

The above mentioned shortcomings, disadvantages and problems areaddressed herein and which will be understood by reading and studyingthe following specification.

OBJECTS OF THE EMBODIMENTS Definitions of the Terms Used and Objects ofthe Embodiments

“Continuous polymer film” would generally mean a polymer film ofunbroken structure

“Continuous Coating layer” would generally mean an unbroken coatingstructure

“Continuous Coating process” would generally mean a process of applyingcoating is uninterrupted

“Continuous structure” would generally mean an unbroken structure

“Coating edge” or “edge” unless specified, would generally mean a narrowstrip of coating layer at the end of the coating layer

“Uncoated surface area” would generally mean a surface area without anycoating

“Composite Layer” would generally mean a layer made up of more than onelayer of same or different material

“Overlap Layer” would generally mean a layer formed by two edges of twoseparate layers, where an edge of one layer goes over the edge ofanother layer forming the overlap layer

“Distinct Layer” would generally mean a layer which is chemically,physically, or structurally different from other layers that are a partof the same structure, the distinctness of the layer is visible eitherthrough the microscope or to the naked eye.

“Sealing layer” would generally mean when an edge of one polymer layeris joined or welded with an edge of another polymer layer to form acontinuous structure

“Distinct Sealing Layer” would generally mean a sealing layer which isdifferent than the rest of the continuous layer and appear as distinctlayer when viewed through the microscope and sometimes to the naked eye.

“Partially coated fertilizer” would generally mean a coated fertilizerpellet having a continuous coating that covers only a part of the totalsurface area of the fertilizer pellet

“Melt fusion” would generally mean when two polymer layers are bondedtogether with the assistance of heat; melt fusion alters the polymerstructure of the composite layer formed due to the polymer chainentanglement.

“Thermal Lamination” would generally mean bonding of two polymer layersunder heat

“Cold lamination” would generally mean bonding of two polymer layersusing chemical bonding method such as using a curable/cold adhesive tobond two layers

“Film Extrusion” would generally mean extrusion of flat polymer filmusing conventional extrusion equipment such as cast film extrusion

“Extrusion Coating” would generally mean coating of polymer by usingconventional extrusion coating equipment such as film extruder andextrusion coating die

“Slot Die Coating” would generally mean coating of polymer using slotdie coating equipment such as a slot die coating system supplied byNordson Corporation, Ohio, USA

“Melt Spray Coating” would generally mean coating of a substrate byspraying of a molten polymer material

“Commercial films” would generally mean polymeric films supplied by filmmanufacturers

“Commercial polymers” would generally mean ready to use polymericmaterials available for film extrusion from commercial suppliersincluding blends that can be prepared from the extrusion gradecommercial resin.

“Polymer Melt” would generally mean a polymer film or coating layer in asoftened state so that the film can be molded or thermoformed

“solid article” would generally mean any three-dimensional article thatcan hold its shape un-assisted

“fertilizer pellet” would generally mean any commercially availablefertilizer of any shape (tablet, briquette, spike, granular, compacted)

“physical properties” “chemical properties”, or “mechanical properties”are properties as understood in the polymer film industry

“band” would generally mean a strip of coating layer

The primary object of the embodiments herein is to provide a system andmethod for manufacturing a polymer coated controlled release fertilizerswith a desired coating of uniform thickness in a single pass and in ahigh speed.

Another object of the embodiments herein is to develop a system andmethod for manufacturing polymer coated granules to enable a use offertilizer granule of even and irregular shapes.

Yet another object of the embodiments herein is to develop a system andmethod for manufacturing a polymer coated controlled release fertilizersto enable a use of fertilizers in tablets, spikes, briquettes, orpellets shape.

Yet another object of the embodiments herein is to develop a system andmethod for manufacturing polymer-coated fertilizers to obtain a polymercoated fertilizer that prevents caking or agglomeration duringtransportation.

Yet another object of the embodiments herein is to develop a system andmethod for manufacturing a polymer coated controlled release fertilizersto enable a use of any commercially available polymer to coat thefertilizer without requiring any solvent or curing, or catalyst forforming the coating onto the fertilizer granule.

Yet another object of the embodiments herein is to develop a system andmethod for manufacturing a polymer coated controlled release fertilizersto allow a complete control of coating application onto the fertilizergranules to achieve a uniform and precise coating thickness.

Yet another object of the embodiments herein is to develop a system andmethod for manufacturing a polymer coated controlled release fertilizersto apply multiple polymer layers simultaneously thereby allowing themanufacturer to produce the fertilizers coated with multiple polymerlayers.

Yet another object of an embodiment herein is to develop a system andmethod for manufacturing a polymer coated controlled release fertilizersto obtain the polymer coated fertilizer and fertilizer products with adesired coating thickness in a single pass thereby saving time, spaceand energy.

Yet another object of an embodiment herein is to develop a system andmethod for manufacturing a polymer coated controlled release fertilizersto obtain the polymer coated fertilizers and fertilizer products with adesired water vapor transmission rate (WVTR) thereby making a highlyeffective controlled release fertilizer products.

Yet another object of an embodiment herein is to develop a system andmethod for manufacturing a polymer coated controlled release fertilizersto obtain polymer coated fertilizers and fertilizer products with adesired duration of biodegradation so that the coating is degraded in apredetermined duration

These and other objects and advantages of the embodiments herein willbecome readily apparent from the following detailed description taken inconjunction with the accompanying drawings.

SUMMARY

The various embodiments herein, provide a system and method formanufacturing polymer-coated fertilizers. According to an embodimentherein, the fertilizer granules are coated in two steps. In the firststep, the first surface area of the fertilizer pellets are coated by acontinuous first coating layer, this creates a partially coated pelletwith one surface coated with a continuous first coating layer.Thereafter a second continuous coating layer is applied onto theremaining uncoated surface of the fertilizer granule to coat theremaining uncoated surface of the pellet. The application of the secondcoating layer coats the second surface in a continuous coating layer andalso creates an overlap layer with the first coating layer where an edgeof the second continuous polymer film goes over the edge of the firstcoating layer and binds with it. The overlap layer is a distinct layerfrom the first coating layer and the second coating layer, and isvisible as a distinct layer when viewed under the microscope in all theembodiments, and to the naked in some embodiments. The encapsulatedfertilizer between the first coating layer, the second coating layer,and the overlap layer is releasable over a time period or interval bydiffusion through the first coating layer, the second coating layer, orthe overlap layer.

Overlap layer formed by melt fusing the edge of the first coating layerwith the edge of the second coating layer is a composite layer, since itis made by joining two polymer structures the properties of the overlaplayer such as chemical properties, physical, properties, or mechanicalproperties would be distinct from the first coating layer and the secondcoating layer due to the change in thickness of the overlap layer,change in polymer chain rearrangement, change in crystalline structure,or air bubbles getting trapped in the interface layer of two edges ofthe two coating layers.

According to an embodiment herein, a polymer coated fertilizer pelletencapsulated in three layers; a first coating layer, a second coatinglayer, and an overlap layer. The fertilizer is releasable through thefirst coating layer, the second coating layer, or the overlap layer. Thethree layers are a part of a continuous structure where the firstcoating layer is on one side and the second coating layer are on theother side of the overlap layer, the first coating layer covers a partof the surface area of the pellet, a second coating layer covers anotherpart of the surface area of the pellet, and the overlap layer where anedge of the first coating layer joins with an edge of the second coatinglayer to form the overlap layer covers a different part of the surfacearea of the pellet,

According to an embodiment herein, first coating layer and the secondcoating layer are separated by a narrow strip of overlap layer such thatthe first coating layer is on the one side and the second coating layeris on the another side of the overlap layer.

According to an embodiment herein, a polymer encapsulated fertilizerpellet having its surface area covered by three layers; first coatinglayer covering a first surface, a second coating layer covering a secondsurface area, and overlap layer covering a third surface area of thepellet, wherein the first surface area, the second surface area, and thethird surface area are different surface areas of the fertilizer pellet.

According to an embodiment herein, a method of manufacturing polymercoated fertilizer comprising; coating a first surface of a fertilizerpellet with a first continuous polymer film, thereafter applying asecond continuous polymer film to coat a second surface of thefertilizer pellet, and sealing a part of the first polymer film with apart of the second polymer film onto the surface of fertilizer pellet sothat the fertilizer pellet is completely encapsulated between the firstpolymer film, the second polymer film, and the distinct overlap layer.The coating layer encapsulating the fertilizer pellet having firstpolymer film, second polymer film, and the overlap layer whereas theoverlap layer seals the two polymer films onto the surface of thefertilizer pellet such that the first polymer film is on one side of theoverlap layer while the second polymer film is on the other side of thesealing layer, the polymer coated fertilizer produced herein releasesthe fertilizer through the first polymer film, the second polymer film,or the sealing layer in a controlled-release manner when applied to thesoil.

According to an embodiment herein, a method of manufacturing polymercoated fertilizer comprising; placing plurality of fertilizer pelletsinto a plurality of housing cavity, applying a first continuous coatinglayer onto the first surface area of the fertilizer pellet, thereafter avacuum suction is applied underneath the fertilizer pellets through anopening in the cavity, the vacuum suction pulls the first coating layeraround the fertilizer pellet coating the first surface area with thefirst continuous coating layer creating a partially coated fertilizerpellet, thereafter the partially coated fertilizer pellets are turnedover to expose the uncoated surface area of the partially coatedfertilizer pellets. Thereafter, a second continuous coating layer isapplied onto the partially coated fertilizer pellets, the second coatinglayer is applied to coat the second surface area of the fertilizerpellets, the second coating layer coats the remaining uncoated surfacearea of the partially coated fertilizer pellets, and an edge of thesecond coating layer goes over an edge of the first coating layercreating an overlap layer area between the first coating layer andsecond coating layer, wherein the overlap layer comprises a part of thefirst coating layer and a part of the second coating layer bondedtogether to form a composite layer that is distinct from the firstcoating layer and the second coating layer, the second coating layerforms the top layer of the overlap layer and the first coating layerforms the bottom layer of the overlap layer, the overlap layer runsalong the circumference of the fertilizer pellet encircling thefertilizer pellet, the overlap layer appears as a distinct layer eitherthrough the naked eye or when viewed under the microscope, thefertilizer pellet encapsulated between the first coating layer, thesecond coating layer, and the overlap layer is releasable through thefirst coating layer, the second coating layer, or the overlap layer.

According to an embodiment herein, a fertilizer pellet is encapsulatedin three distinct coating layers covering three different surfaces ofthe fertilizer pellet; first continuous coating layer covers a firstsurface area, a second continuous layer covers a second surface area,and a composite layer covers a third surface area, wherein the firstcoating layer, the second coating layer, and the composite layer aredistinct from each other, the first coating layer, the second coatinglayer, and the composite layer form a single continuous coatingstructure that encapsulate the fertilizer pellet.

According to an embodiment herein, a polymer coated fertilizer pelletcomprises; a fertilizer pellet, a first continuous coating layercovering a first surface area of the fertilizer pellet, a secondcontinuous coating layer covering a second surface area of thefertilizer pellet, and an overlap area covering a third surface area ofthe fertilizer pellet, the overlap layer laminates the first coatinglayer and the second coating layer onto the surface of the fertilizerpellet so that the fertilizer pellet is completely encapsulated betweenthe first continuous coating layer, the second continuous coating layer,and the overlap layer. The first coating layer and the second coatinglayer are on the opposite surfaces of the fertilizer pellet coatingdifferent surfaces of the fertilizer pellet, overlap layer is acomposite layer comprising an edge of the first coating layer and anedge of the second coating layer; the fertilizer pellet encapsulatedbetween the first coating layer, the second coating layer, and theoverlap layer is controlled-release fertilizer and is releasable throughthe first coating layer, the second coating layer, and/or the overlaplayer providing nutrients or the plant protectant to the growing plant.

According to an embodiment herein, a system for coating a plurality ofarticles in a continuous process using a melt extruded polymer film isprovided. The system comprises; placing the solid articles in a housingcavity, extruding a first polymer film onto the first surface of thesolid article, applying vacuum to coat first polymer film around thefirst surface of the solid articles, the application of the firstpolymer film creates a partially coated solid articles where the firstpolymer film covers the first surface of the solid article, thereafterturning over the partially coated solid articles to expose the secondsurface of the partially coated solid article, the second surface of thesolid article is the uncoated surface of the sold article, thereafter asecond polymer film is extruded and applied onto the second surface ofthe partially coated fertilizer, vacuum is applied underneath thepartially coated fertilizer so as to thermoform the second polymer filmaround the second surface of the solid pellet and also to melt fuse apart of the second polymer film with a part of the first polymer filmforming a melt fused overlap layer comprising an edge of the firstpolymer film and an edge of the second polymer film; the solid articleencapsulated between the first coating layer, the second coating layer,and the overlap layer is releasable through the first coating layer, thesecond coating layer, or the overlap layer in a controlled-releasemanner.

According to an embodiment herein, the thickness of the first coatinglayer, the second coating layer, and the composite layer is within arange of 5 microns to 300 microns. The desired temperature at which thefirst coating layer and the second coating layer is coated around thesurface of the fertilizer pellet is between a range of 50 degreecentigrade to 500 degree centigrade. The desired chemical property ofthe first coating layer and the second coating layer is water vapourtransmission rate (WVTR), as understood in the polymer film industry.The WVTR value of the first coating layer, the second coating layer, andthe composite layer is between the range of 1 g/(m²·day) to 2000g/(m²·day).

According to an embodiment herein, the desired thickness of the firstpolymer film, the second polymer film, and composite film is within arange of 5 microns to 300 microns. The desired chemical property of thefirst polymer film, the second polymer film, and the composite film iswater vapour transmission rate (WVTR). The WVTR value of the firstpolymer film and the second polymer film is within a range of 1g/(m²·day) to 2000 g/(m²·day).

According to one embodiment herein, the first and second polymer film ismade from any extrusion grade polymer capable of producing a film. Thepolymer film can be applied as coating layer wherein the surfacetemperature of the film is between a range of 50° C. to 500° C. at thetime of coating.

According to an embodiment herein, a system for coating a plurality ofarticles in a continuous process using a polymer melt is provided. Thesystem comprises a feeding mechanism connected to a first chill roll tosupply a plurality of articles. The first chill roll comprises aplurality of first cavities on a peripheral surface and the plurality offirst cavities houses and holds a plurality of articles. A first machineis provided for producing a first molten film and applying the firstmolten film on the plurality of articles held in the plurality of firstcavities in the first chill roll to partially coat the plurality ofarticles with the first molten film. A second chill roll is placed at aside of the first chill roll or the second chill roll is placed on a topside of the first chill roll to receive a plurality of articlespartially coated with a first molten film. A second machine is providedfor producing and applying the second molten film on the plurality ofarticles held in the plurality of second cavities in the second chillroll and partially coated with the first molten film. A collectormechanism is provided to receive the plurality of articles coated withthe first molten film and the second molten film from the second chillroll.

According to an embodiment herein, a system for coating a plurality ofarticles in a continuous process using a polymer melt is provided. Thesystem comprises a first chill roll, a second chill roll, a firstmachine, a second machine, a feeding mechanism and a collectormechanism.

According to an embodiment herein, the first chill roll comprises aplurality of first cavities on a peripheral surface and the plurality offirst cavities houses and holds a plurality of articles.

According to an embodiment herein, the second chill roll is identical tothe first chill roll. The second chill roll is placed at a side of thefirst chill roll or the second chill roll is placed on a bottom side ofthe first chill roll. The second chill roll comprises a plurality ofsecond cavities on a peripheral surface. The plurality of secondcavities houses and holds a plurality of articles received from thefirst chill roll. The plurality of second cavities in the second chillroll matches with the plurality of first cavities in the first chillroll. The plurality of second cavities in the second chill roll and theplurality of first cavities in the first chill roll are arranged to faceeach other.

According to an embodiment herein, the system comprises a first machinefor producing a first molten film and applying the first molten film onthe plurality of articles held in the plurality of first cavities in thefirst chill roll to partially coat the plurality of articles with thefirst molten film. The first molten film has a desired thickness, widthand chemical properties. The first machine comprises a first polymerextruder and a first film molding die. The first polymer extruder mixes,melts and extrudes a polymer to generate a homogenous melt of polymer.The first film molding die is attached to an end of the first polymerextruder for receiving a molten feed from the first polymer extruder toproduce the first molten film of desired thickness and width. Thepolymer is a single polymer or a blend of polymers.

According to an embodiment herein, the system comprises a second machinefor producing a second molten film and applying the second molten filmon the plurality of articles held in the plurality of second cavities inthe second chill roll. The second molten film has a desired thickness,width and chemical properties. The second machine comprises a secondpolymer extruder and a second film molding die. The second polymerextruder mixes, melts and extrudes a polymer to generate a homogenousmelt of polymer. The second film molding die is attached to an end ofthe polymer extruder for receiving a molten feed from the second polymerextruder to produce the second molten film of desired thickness andwidth. The polymer is a single polymer or a blend of polymers.

According to an embodiment herein, the system comprises a feedingmechanism for feeding the plurality of articles to the first chill rolland a collection mechanism for collecting the plurality of articles fromthe second chill roll. The plurality of articles collected from thesecond chill roll are coated with the first polymer film at one side ofthe plurality of articles and with the second polymer film at anopposite side of the plurality of articles so that the plurality ofarticles are encapsulated within the first polymer film and the secondpolymer film. The plurality of articles is a controlled release article.

According to an embodiment herein, the plurality of articles is selectedfrom a group consisting of a fertilizer, a pharmaceutical tablet, adetergent tablet, a biocide tablet, a pesticide granule, an animal feedand a food particle. The plurality of articles is water soluble. Theplurality of articles is selected from a group consisting of a polymercoated articles.

According to an embodiment herein, the mean article size is within therange of 1 mm to 150 mm.

According to an embodiment herein, the system further comprises acutting mechanism provided at the first chill roll and the second chillroll to cut the first polymer film and the second polymer film afterapplication on the plurality of articles. The cutting mechanism is asharp cutting edge provided on the surface of the first chill roll andthe second chill roll.

According to an embodiment herein, the system further comprises a rotarypin to push the plurality of articles held at the plurality of secondcavities in the second chill roll, when the second polymer film isapplied on the plurality of the articles coated partially with the firstpolymer film.

According to an embodiment herein, the first chill roll is rotated in aclockwise direction through a desired angle for receiving the pluralityof articles at the plurality of first cavities. The second chill roll isrotated in an anti-clockwise direction through a desired angle forreceiving the plurality of articles at the plurality of cavities. Thefirst chill roll and the second chill roll are rotated in a synchronizedmanner in the clockwise direction and in the anti-clockwise directionrespectively so that at least one of the plurality of first cavities inthe first chill roll is arranged opposite to at least one of theplurality of second cavities in the second chill roll to transfer theplurality of articles in the first cavities of the first chill roll tothe plurality of second cavities in the second chill roll.

According to an embodiment herein, the first chill roll and the secondchill roll comprise an internal fluid circulation mechanism forcirculating a fluid to control a surface temperature of the first chillroll. The first chill roll and the second chill roll comprise anon-stick coating on an outer surface to avoid a sticking of the moltenfilm onto the surface of the chill roll. The first chill roll and thesecond chill roll are rotatable cylindrical drums.

According to an embodiment herein, each of the plurality of firstcavities and each of the plurality of second cavities hold one article.The plurality of first cavities and the pluralities of the secondcavities are arranged in a shape selected from a group consisting of atablet, spike, circular, rectangular, square and hexagonal shapes. Eachone of the plurality of first cavities and each one of the plurality ofsecond cavities holds at-least one article by a vacuum. The plurality offirst cavities and the plurality of second cavities comprise an openingor hole in a bottom to provide the vacuum for holding the plurality ofarticles. A size of the plurality of first cavities is larger than asize of the plurality of articles and a size of the plurality of secondcavities is larger than a size of the plurality of articles. Theplurality of first cavities and the plurality of second cavitiescomprise a compressable cushion ring in a bottom. The cushion ring ismade up of a material selected from a group consisting of a soft rubbermaterial or a rubber like material.

According to an embodiment herein, the first polymer film die and thesecond polymer film die is any one of a curtain coating and a slot dye.The first polymer film die and the second polymer film die produce asingle layer polymer film or a multilayer polymer film. According to anembodiment herein, the polymer is melt processed into a molten film ofdesired thickness.

According to an embodiment herein, the first polymer film is coated onthe surface of the plurality of articles in a range of 1%-99%. Thesecond polymer film is coated on the surface of the plurality ofarticles coated partially with the first polymer film in a range of1%-99%.

According to an embodiment herein, the first polymer film and the secondpolymer film comprise one or more additives. The one or more additivesare selected from a group consisting of hydrophilic additives,surfactants, inorganic minerals, biodegradable additives, pigments andwater soluble additive. The hydrophilic additives are added forincreasing a moisture permeability of the first polymer film and thesecond polymer film.

According to an embodiment herein, the inorganic mineral is selectedfrom a group consisting of talc, calcium carbonate, mica, silica andtheir derivatives. The inorganic minerals are added for modifying amoisture permeability, reducing a temperature induced expansion of thefirst polymer film and the second polymer film, and reducing a tackinessof the first polymer film and the second polymer film, and preventing acaking or agglomeration of the plurality of articles coated with thefirst polymer film and the second polymer film.

According to an embodiment herein, wherein the biodegradable additivesare added for adding a biodegradable characteristics to the firstpolymer film and the second polymer film and for expediting abiodegradation of the first polymer film and the second polymer film.The additives are added to the first polymer film and the second polymerfilm layer in a range of 0.01%-50% of a combined dry weight of the firstpolymer film and the second polymer film.

According to an embodiment herein, the desired thickness of the firstpolymer film and the second polymer film is within a range of 5 micronsto 300 microns. The desired temperature of the first molten polymer filmand the second molten polymer film is within a range of 50° C. to 500°c. The desired chemical property of the first polymer film and thesecond polymer film is water vapor transmission rate (WVTR). The desiredWVTR of the first polymer film and the second polymer film is within arange of 0.001 g/(m²·day) to 20000 g/(m²·day).

According to an embodiment herein, a method is provided for coating aplurality of articles in a continuous process using a polymer. Themethod comprises extruding and applying a first coating layer with afirst molten polymer film on a plurality of articles held on a pluralityof first cavities in a first chill roll for generating a plurality ofarticles coated partially with the first polymer film. The plurality ofarticles coated partially with the first polymer film is transferredfrom the first chill roll to a second chill roll. An uncoated portion ofthe plurality of articles coated partially with the first polymer filmis exposed. A second coating layer of a second molten polymer film isextruded and applied on the plurality of articles held on a plurality ofsecond cavities in the second chill roll for generating a plurality ofarticles fully coated with the first polymer film and the second polymerfilm. The plurality of articles is encapsulated between the firstcoating layer and the second coating layer by sealing the first polymerfilm and the second polymer film coated on the plurality of articles bymelt fusing the second polymer film with the first polymer film on anoverlapping area of the first polymer film and the second polymer film.The encapsulated plurality of articles is released over a time period bya diffusion of the encapsulated plurality of articles through the firstpolymer film or the second polymer film.

According to an embodiment herein, the plurality of articles are held inthe plurality of first cavities and in the plurality of second cavitiesby a vacuum suction adopted at a bottom of the plurality of firstcavities and at the plurality of second cavities. A pulling force of thevacuum suction under the plurality of articles is adapted to pull thefirst polymer film and the second polymer film around the plurality ofarticles and to adhere the first polymer film and the second polymerfilm respectively to an opposing surface of the plurality of articles.

According to an embodiment herein, the mean article size is within 1 mmto 150 mm.

According to an embodiment herein, the first polymer film is coated onthe surface of the plurality of articles in a range of 1%-99%. Thesecond polymer film is coated on the surface of the plurality ofarticles coated partially with the first polymer film in a range of1%-99%.

According to an embodiment herein, the polymer is melt processed into amolten film.

According to an embodiment herein, the first polymer film and the secondpolymer film comprises one or more additives. The one or more additivesare selected from a group consisting of hydrophilic additives,surfactants, inorganic minerals, biodegradable additives, pigments andwater soluble additive. The hydrophilic additives or surfactants areadded for increasing a moisture permeability of the first polymer filmand the second polymer film.

According to an embodiment herein, the inorganic mineral is selectedfrom a group consisting of talc, calcium carbonate, mica, silica andtheir derivatives. The inorganic minerals are added for modifying amoisture permeability, reducing a temperature induced expansion of thefirst polymer film and the second polymer film, and reducing a tackinessof the first polymer film and the second polymer film, and preventing acaking or agglomeration of the plurality of articles coated with thefirst polymer film and the second polymer film.

According to an embodiment herein, the biodegradable additives are addedfor adding a biodegradable characteristic to the first polymer film andthe second polymer film and for expediting a biodegradation of the firstpolymer film and the second polymer film.

According to an embodiment herein, the additives are added to the firstpolymer film and the second polymer film layer in a range of 0.01%-50%of a combined dry weight of the first polymer film and the secondpolymer film.

According to an embodiment herein, the desired thickness of the firstpolymer film and the second polymer film is within a range of 5 micronsto 300 microns. The desired temperature of the first molten polymer filmand the second molten polymer film is within a range of 50° C. to 500°c. The desired chemical property of the first polymer film and thesecond polymer film is water vapour transmission rate (WVTR). The WVTRvalue of the first polymer film and the second polymer film is within arange of 0.01 g/(m²·day) to 20,000 g/(m²·day).

According to an embodiment herein, the first chill roll and the secondchill roll are rotatable cylindrical drums.

According to an embodiment herein, a method for manufacturing acontrolled release fertilizer involves placing the fertilizer granulesonto a surface and applying a first layer of polymer onto the exposedsurface of the fertilizer granule. Then the uncoated portion offertilizer is exposed and a second layer of polymer is applied toencapsulate the fertilizer granule between the first polymer layer andthe second polymer layer such that the fertilizer granules arereleasable over a time by a diffusion through at least one of the firstpolymer film or the second polymer film.

According to one embodiment herein, the manufacturing process ofpolymer-coated fertilizers has two main steps. In the first step, thefertilizer granules are partially coated by a first polymer film.Thereafter a second polymer film is applied onto the remaining uncoatedfertilizer granule surface thereby encapsulating the fertilizer betweenthe two polymer films.

According to one embodiment herein, an apparatus for coating pluralityof articles in a continuous process using polymer melt comprises a firstchill roll, a second identical chill roll, a first machine, a secondmachine, a feeding mechanism and a collection mechanism. The first chillroll comprises a plurality of cavities placed side by side and on theperiphery of the first chill roll. The cavities are capable of holdingthe articles. The second identical chill roll comprises plurality ofcavities placed side by side and on the periphery of second chill rolland the cavities of first and second chill rolls are facing each other.The first machine is used for producing a molten film of desiredthickness, width and properties. The first polymer film is placed insuch a way that the molten polymer film is applied directly onto thearticles held in the cavity of the first chill roll. The second machineis adapted for producing a molten film of desired thickness, width andproperty. The second machine is placed in such a way that the moltenfilm is applied directly onto the articles held in the cavity of thesecond chill roll. The feeding mechanism is for feeding the articlesonto the first chill roll. The collection mechanism is for collectingcoated articles from the second chill roll.

According to one embodiment herein, the chill roll is a cylindrical drumcapable of rotating. The chill roll has a plurality of cavities on thecircumferential surface of the roll. The chill roll has an internalfluid circulation to control a surface temperature of the chill roll.The chill roll has a non stick coating applied on the surface of theroll. The chill roll rotates in a synchronized way so that cavities onthe surface of the first chill roll always face the identical cavitieson the second chill roll.

The cavity of the chill roll is of any shape and dimension. The cavityof the chill roll is suitable for holding the articles being coated. Theshape of the cavity is chosen from a tablet, spike, circular,rectangular, square or hexagonal shape. The cavities are distributed allover the circumference of the first and second chill roll. Further thecavities are of larger dimension than that of the articles being coated.The cavities have soft rubber or rubber like compressable cushion ringsin the bottom. The cavity has an opening/hole in the bottom throughwhich a vacuum suction is provided to hold the articles. Further thearticles are housed in the cavity and held with the vacuum suction inthe cavity. Only one article is housed per cavity.

According to one embodiment herein, the first and second machine usedfor producing a molten film comprises a polymer extruder and a film die.The polymer extruder is capable of mixing, melting and extruding anycommercially available polymer or blend of polymers or additives andcreating a homogenous melt. The polymer film die is capable of producinga molten film of desired thickness width and properties from the polymerfilm melt produced by the extruder. The die is attached to the end ofthe extruder.

According to one embodiment herein, the film die is a curtain coatingdie or slot die capable of producing a polymer film using polymer melt.The film die has a single layer or multilayer polymer film extrusioncapability. The film die is a commercially available extrusion diecapable of producing a molten polymer film of desired thickness, andwidth.

According to one embodiment herein, the method for coating thefertilizers is initiated by feeding the articles on the first chill rollwhere the articles are held in the cavities by the vacuum suction at thebottom of the cavity. The next step is extruding a first layer of moltenpolymer film on the articles. The pull of vacuum suction under the saidarticles pulls the molten polymer layer around the articles to adherethe molten film to the surface of the article to create a partiallycoated article. Further the partially coated articles are transferred tothe cavity of the second chill roll and the uncoated portion of thepartially coated particles is exposed. A second layer of molten polymeris extruded and applied on the uncoated portion of the partially coatedarticles in such a way that second coating layer overlaps the firstcoating layer and the high temperature of the molten second layer helpsin laminating the second layer with the overlapping area of the firstlayer. Hence the fertilizer particle or an article is sealed orencapsulated between the first polymer layer and second polymer layer.

According to one embodiment herein, the articles are any commerciallyavailable fertilizer granule in any dimension and shape. Further thearticles is any one selected from a group consisting of a detergenttablet of any shape and dimension, a biocide tablet of any shape anddimension, a pesticide granule of any shape and dimension, an animalfeed of any shape and dimension, and a food particle of any shape anddimension. The articles have even or uneven shape. The articles chosenare water soluble.

According to one embodiment herein, the first and second polymer film isany extrusion grade polymer capable of producing a film of desiredthickness and properties. The molten polymer film withstands atemperature range of 50° C.-500° C. The thickness of the polymer film isin the range of 5-300 micron. Further, the desired chemical property ofthe first polymer film and the second polymer film is water vaportransmission rate (WVTR). The WVTR value of the first polymer film andthe second polymer film is within a range of 0.01 g/(m²·day) to 20,000g/(m²·day).

According to one embodiment herein, the partially coated articles havethe polymer coat covering in the range of 1%-99% of the surface area.Further the second polymer film coating on the partially coated articleshave polymer coat covering in the range of 1%-99% of the surface area,of the coated article.

According to one embodiment herein, a method of producing the controlledrelease delivery systems comprises coating a first layer of polymer ontothe surface of the article creating partially coated articles. Theremaining uncoated portion of the surface area is exposed and appliedwith a second coating layer. The article is sealed between the firstcoating layer and the second coating layer by melt fusing the secondcoating layer with the first coating layer in the overlapping area ofthe first coating layer and the second coating layer. The article isencapsulated between the first coating layer and the second coatinglayer. The encapsulated article between the first coating layer andsecond coating layer is releasable over the time by diffusion throughthe first coating layer or the second polymer film.

According to one embodiment herein, the first polymer film and secondpolymer film have multiple film layers forming a single laminatedcoating layer. The first or second polymer films have additives into thefilm structure. The additives are selected from the group consisting ofhydrophilic additives, surfactants, inorganic minerals, biodegradableadditives and pigments. The hydrophilic additives or surfactants areadded for increasing the moisture permeability of the coating layer.Inorganic minerals such as talc, calcium carbonate, mica or silica ortheir derivatives are added for modifying moisture permeability,reducing a temperature induced expansion of the polymer coating, andreducing a caking or agglomeration of the coated articles. Thebiodegradation additives are added for expediting the biodegradation ofthe coating layer. The pigments are added for providing a color to thecoating films. The amount of additives added to the polymer layer iswithin a range of 0.01%-50% of the combined dry weight of the first orsecond coating layer.

According to one embodiment herein, the first or second polymer film hasmultiple film layers co-extruded to form a single coating layer. Furtherthe multilayer coated films are of different thickness or differentadditives or have additive loading levels.

According to one embodiment herein, cheap polymers are used to coat thefertilizer granules. Further the dry fertilizer granules in any shape,form are coated, thereby eliminating the need for using expensivespherical fertilizer granules. The method of coating the fertilizergranules does not involve any solvent or catalyst. The method gives auniform coating on the fertilizer granules. Furthermore the methodallows an application of multiple polymers simultaneously therebyallowing the manufacturer to produce a fertilizer coated with multiplepolymer layers. The method has ability to apply a coating film withdesired weight in a single time thereby saving time, space and energy toproduce coated products.

These and other aspects of the embodiments herein will be betterappreciated and understood when considered in conjunction with thefollowing description and the accompanying drawings. It should beunderstood, however, that the following descriptions, while indicatingpreferred embodiments and numerous specific details thereof, are givenby way of illustration and not of limitation. Many changes andmodifications may be made within the scope of the embodiments hereinwithout departing from the spirit thereof, and the embodiments hereininclude all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

The other objects, features and advantages will occur to those skilledin the art from the following description of the preferred embodimentand the accompanying drawings in which:

FIG. 1 illustrates a block diagram of a system for manufacturing thepolymer coated fertilizers, according to an embodiment herein.

FIG. 2 illustrates a schematic view of a partially coated fertilizergranules obtained from a first chill roll in the system formanufacturing the polymer coated fertilizers, according to an embodimentherein.

FIG. 3 illustrates a schematic view of the full coated fertilizergranules, obtained from a second chill roll in the system formanufacturing the polymer coated fertilizers, according to an embodimentherein.

FIG. 4 illustrates a schematic view of a first machine for applying afirst polymer film and the polymer film breaking mechanism in the systemfor manufacturing the polymer coated fertilizers, according to anembodiment herein.

FIG. 5 illustrates a schematic view of a second machine for applying asecond polymer film with the polymer film cutting mechanism and a rotarypin for pushing the fertilizer granules through the cavity in the systemfor manufacturing the polymer coated fertilizers, according to anembodiment herein.

FIG. 6 illustrates a schematic view of a partially coated fertilizerpellet 107 having a continuous coating layer 105 covering a firstsurface area 101 a of the fertilizer pellet 101 obtained after theapplication of the first coating layer 105 for manufacturing the polymercoated fertilizers, according to an embodiment herein. First coatinglayer 105 has a continuous structure and an edge 105 a, wherein the edge105 a is a narrow strip at the end of first coating layer structure.

FIG. 7 illustrates a schematic view of the completely coated fertilizerpellet 109 having first continuous coating layer 105, second continuouscoating layer 108, and an overlap layer 201, obtained after theapplication of the second coating layer for manufacturing the polymercoated fertilizers, according to an embodiment herein. The overlap layer201 is formed by bonding the edge 105 a of the first coating layer 105with edge 108 a of the second coating layer 108 onto the surface of thefertilizer pellet 101.

FIG. 8 illustrates a schematic view of a polymer coated fertilizerpellet encapsulated between a first coating layer 105, a second coatinglayer 108, and an overlap layer 201 obtained after the application ofthe second coating layer for manufacturing the polymer coatedfertilizers, according to an embodiment herein. As presented in FIG. 8 ,first coating layer 105, the second coating layer 108, and the overlaplayer 201 cover different parts of the surface of the fertilizer pellet101.

Although the specific features of the present invention are shown insome drawings and not in others. This is done for convenience only aseach feature may be combined with any or all of the other features inaccordance with the present invention.

DETAILED DESCRIPTION OF DRAWINGS

In the following detailed description, a reference is made to theaccompanying drawings that form a part hereof, and in which the specificembodiments that may be practiced is shown by way of illustration. Theseembodiments are described in sufficient detail to enable those skilledin the art to practice the embodiments and it is to be understood thatthe logical, mechanical and other changes may be made without departingfrom the scope of the embodiments. The following detailed description istherefore not to be taken in a limiting sense.

According to an embodiment herein, the fertilizer pellets are coated intwo steps. In the first step, the first surface area of the fertilizerpellets is coated by a continuous first coating layer, this creates apartially coated pellet having one surface coated with a continuousfirst coating layer. Thereafter a second continuous coating layer isapplied onto the remaining uncoated surface of the fertilizer granule tocoat the remaining uncoated surface area of the pellet. The applicationof the second coating layer coats the second surface in a continuouscoating layer. A part of the second coating layer binds with a part ofthe first coating layer over the surface of the fertilizer pellet andcreates a composite overlap layer. The composite overlap layer isdistinct from the first coating layer and the second coating layer, andis visible as a distinct layer when viewed through a microscope. Theencapsulated fertilizer between the first coating layer, the secondcoating layer, and the composite overlap layer is releasable over a timeperiod or interval by diffusion through the first coating layer, thesecond coating layer, and the overlap layer.

According to an embodiment herein, presented in FIG. 8 , a fertilizerpellet 101 is encapsulated in a three part continuous coated layer; afirst coating layer 105 covers a first surface area of the fertilizerpellet 101, a second coating layer 108 covers a second surface area ofthe fertilizer pellet 101, a third coating layer 201 covers a thirdsurface area of the fertilizer pellet 101, the third coating layer is anoverlap layer formed by bonding a part of first coating layer with apart of the second coating layer on the surface of the fertilizer pellet101, fertilizer encapsulated between the first coating layer, the secondcoating layer, and the third coating layer is releasable through any orall of the said three coating layers.

According to an embodiment herein, presented in FIG. 7 ; a polymercoated fertilizer pellet 109. A first coating layer 105 having acontinuous structure and an edge 105 a. The edge 105 a is the narrowstrip of layer at the end of the coating layer 105. The continuousstructure of the first coating layer covers a first surface of thefertilizer pellet 101. A second coating layer 108 has a continuousstructure and an edge 108 a. The edge 108 a is the narrow strip of layerat the end of the coating layer 108. The continuous structure of thesecond coating layer covers a second surface of the fertilizer pellet.The edge 105 a of the first coating layer 105 and the edge 108 a of thesecond coating layer 108 join together to form a distinct compositeoverlap layer 201. The Composite overlap layer covers a third surface ofthe fertilizer pellet 101. Polymer coated fertilizer pellet 109 isencapsulated in the first coating layer 105 covering a first surface,the second coating layer 108 covering a second surface, and the overlaplayer 201 covering a third surface. The fertilizer encapsulated in thefirst coating layer, the second coating layer, and the overlap layer isreleasable through the first coating layer, the second coating layer, orthe overlap layer.

FIG. 7 and FIG. 8 ; Overlap layer formed by binding the edge 105 a ofthe first coating layer 105 with the edge 108 a of the second coatinglayer 108 is a composite overlap layer 201. Since overlap layer 201 itis made by joining two polymer structures the properties of the overlaplayer 201 such as chemical, physical, properties, or mechanicalproperties would be distinct from the first coating layer 105 and thesecond coating layer 108 due to either change in thickness, change inpolymer chain rearrangement, change in crystalline structure, or airbubbles getting trapped at the interface of edge 105 a and edge 108 a.The interface is the surface where the edge 105 a of the first coatinglayer 105 joins with the edge 108 a of the second coating layer 108.

FIG. 7 , FIG. 8 : According to an embodiment herein, Polymer coatedfertilizer pellet 109 is encapsulated in a first coating layer 105covering a first surface of the fertilizer pellet 101, a second coatinglayer 108 covering a second surface of the fertilizer pellet, and anoverlap layer 201 covering a third surface of the fertilizer pellet, thefertilizer encapsulated in the first coating layer, the second coatinglayer, and the overlap layer is releasable through the first coatinglayer, the second coating layer, or the overlap layer. Wherein the firstcoating layer, the second coating layer, and the overlap layer aredistinct from each other.

According to an embodiment herein, As presented in FIG. 8 , Polymercoated fertilizer pellet 109 comprises three layers; a first coatinglayer 105 having thickness between 5 microns to 300 microns and watervapor transmission rate (WVTR) between 1 g/(m²·day) to 2000 g/(m²·day),a second coating layer 108 having thickness between 5 microns to 300microns and water vapor transmission rate (WVTR) between 1 g/(m²·day) to2000 g/(m²·day), and a composite overlap layer 201 having thicknessbetween 5 microns to 300 microns and water vapor transmission rate(WVTR) between 1 g/(m²·day) to 2000 g/(m²·day). The first coating layercovers a first surface of the fertilizer pellet 101, second coatinglayer 108 covers a second surface of the fertilizer pellet 101, and thecomposite overlap layer covers a third surface of the fertilizer pellet101. The fertilizer pellet 101 in polymer coated fertilizer 109 isreleasable through the first coating layer 105, the second coating layer108, and the composite overlap layer 201.

According to an embodiment herein FIG. 7 and FIG. 8 , a continuouscoating layer encapsulating the fertilizer pellet 101 comprises; threeseparate but continuous structures; 1) first coating layer 105, 2) thesecond layer 108, and 3) the overlap layer 201. The three layers (105,108, and 201) are a part of continuous structure where the first layer105 is separated by a strip of overlap layer 201 such that the firstcoating layer 105 is on one side and the second coating layer 108 is onthe other side of the overlap layer 201.

As shown in FIG. 6 , FIG. 7 , and FIG. 8 , first surface 101 a and thesecond surface 101 b are the opposite surfaces of the fertilizer pellet101.

According to an embodiment herein, as presented in FIG. 7 and FIG. 8Fertilizer pellet 101 having its first surface 101 a coated with a firstpolymer film 105 and second surface 101 b coated with a second polymerfilm 108 and sealing the first polymer film 105 and the second polymerfilm 108 onto the surface of the fertilizer pellet 101 by melt fusing apart 105 a of first polymer film 105 with a part 108 a of the secondpolymer film 108 creating an overlap layer 201 such that the firstpolymer film 105 and the second polymer film 108 are on the oppositeside separated by the overlap layer 201, the distinct sealing layer 201runs along the circumference of the fertilizer pellet 101 dividing thefirst polymer film 105 and the second polymer film 108, the coatedfertilizer 109 produced herein is a controlled-release fertilizer.

According to an embodiment herein, a method of manufacturing polymercoated fertilizer pellet 109 comprises; applying a first coating layer105 onto a first surface 101 a of fertilizer pellet 101 creating apartially coated fertilizer 107 (FIG. 6 ), wherein first coating layerhaving a continuous structure 105 and an edge 105 a, thereafter a secondcoating layer 108 is applied onto the partially coated fertilizer, thesecond coating layer 108 covers a second surface area of the fertilizerpellet 101, the second coating layer 108 covers the second surface ofthe fertilizer pellet in a continuous coating layer and an overlap layer201, the overlap layer 201 is formed by sealing an edge 105 a of thefirst coating layer 105 with an edge 108 a of the second coating layer108 onto the surface of the fertilizer pellet 101, the overlap layer 201seals the edge 105 a of the first coating layer 105 and the edge 108 aof the second coating layer 108 onto the surface of the fertilizerpellet 101 so that the fertilizer pellet 101 is completely encapsulatedbetween the first coating layer 105 and the second coating layer 108,and the overlap layer 201 is releasable through the first coating layer105, the second coating layer 108, or the overlap layer 201 in acontrolled-release manner.

According to an embodiment herein, as presented in FIG. 8 , the overlaplayer 201 has a different thickness than the first coating layer 105 andthe second coating layer 108, the fertilizer pellet 101 encapsulatedbetween the first coating layer 105, the second coating layer 107, andthe overlap layer is releasable through the first coating layer 105, thesecond coating layer 108, and the overlap layer 201.

As presented in FIG. 8 , the first coating layer 105 covers firstsurface of fertilizer pellet, the second coating layer 108 covers secondsurface of fertilizer pellet, and the overlap layer 201 covers thirdsurface of the fertilizer pellet. The third surface of the fertilizerpellet is between the first surface and the second surface.

In all embodiments the polymer coated fertilizer pellet 109 will havethree coating layers that are visible under the microscope or to thenaked eye; the first coating layer 105, the second coating layer 108,and the composite overlap layer 201 (As presented in FIG. 8 ). Firstcoating layer 105 and the second coating layer 108 may be same ordifferent but the overlap layer 201 is always distinct in all theembodiments due to the binding of two polymer structure. Fertilizerpellet 101 is releasable through the first coating layer 105, the secondcoating layer 108, and the overlap layer 201.

The overlap layer 201 encircle the fertilizer pellet 101 like a strip oflayer and is distinct from the first coating layer 105 and secondcoating layer 108 (as shown in FIG. 8 ), the overlap layer 201 hasdifferent physical, structural, or chemical properties than the firstcoating layer 105 and the second coating layer 108

According to an embodiment herein, under the vacuum pull the edge 105 aof the first coating layer and the edge 108 a of the second coatinglayer stretch and the stretching induces orientation in the edge layer.Orientation induced changes cause the property of edge layer to changefrom the rest of the coating layer.

According to an embodiment herein, First Coating layer 105 may have athickness between 5 microns to 300 microns, preferably between 10 micronto 100 microns, most preferably 10 micron to 50 microns. The fertilizerpellet 101 maybe a fertilizer tablet, wherein the diameter of the tabletis between 8 mm to 12 mm and thickness of the tablet is between 4 mm to8 mm.

According to an embodiment herein, As shown in FIG. 7 the overlap layer201 covers the surface of the fertilizer pellet 101 between the tendpoint of the edge 105 a and end point of the edge 108 a. The overlaplayer 201 is a strip of composite layer that runs along thecircumference of the fertilizer pellet 101 (As shown in FIG. 8 ).

According to an embodiment herein; A polymer coated fertilizer for usein agriculture production comprising; a solid pellet of material thatincludes a fertilizer, the solid pellet of material having a surface; afirst coating layer having a continuous structure covering a firstsurface of the pellet; a second coating layer having a continuousstructure covering a second surface of the pellet; whereas the secondcoating layer covers the surface not covered by the first coating layer;a composite overlap layer covering a third surface of the pellet,wherein the composite overlap layer is formed by bonding a part of thefirst coating layer with a part of the second coating layer toencapsulate the pellet between the first coating layer, the secondcoating layer, and the composite overlap layer, wherein the compositelayer is distinct from the first coating layer and the second coatinglayer; and fertilizer pellet encapsulated between the first coatinglayer, the second coating layer, and the composite overlap layer isreleasable through the first coating layer, the second coating layer,and the composite overlap layer over a period of time.

According to an embodiment herein, the fertilizer includes at least oneof the following: an organic fertilizer, an inorganic fertilizer, anatural fertilizer, a synthetic fertilizer, a micronutrient, aninsecticide, a fungicide, a herbicide, a nitrification inhibitor, abioinoculant, a urease inhibitor, an aluminium sulfate.

According to an embodiment herein, wherein the solid pellet of materialincludes one of the following: a tablet, a capsule, a briquette, and agranule.

According to an embodiment herein, wherein the first coating layerincludes at least one of the following: a natural polymer, a syntheticpolymer, a biodegradable polymer, a non-biodegradable polymer, aprocessing additive, a polymer stabilizing additive, an inorganicmineral, a biodegradation additive, a oxo-biodegradation additive, anitrification inhibitor, a urease inhibitor, a hydrogel particle, anorganic surfactant, an inorganic surfactant, a pigment, a chemicaltaggant, a physical taggant, and a pesticide.

According to an embodiment herein, wherein the second coating layerincludes at least one of the following: a natural polymer, a syntheticpolymer, a biodegradable polymer, a non-biodegradable polymer, a polymerprocessing additive, a polymer stabilizing additive, an inorganicmineral, a biodegradation additive, a oxo-biodegradation additive, anitrification inhibitor, a urease inhibitor, a hydrogel particle, anorganic surfactant, an inorganic surfactant, a pigment, a chemicaltaggant, a physical taggant, and a pesticide.

The polymer-coated article of claim 1 wherein fertilizer pellet is aurea tablet having weight between 100 mg to 800 mg.

A polymer coated fertilizer comprising; a solid pellet of material thatincludes a fertilizer, the solid pellet of material having a surface, afirst coating layer having a continuous structure and an edge, whereinthe continuous structure of the first coating layer covers a firstsurface area of the fertilizer pellet, a second coating layer having acontinuous structure and an edge, wherein the continuous structure ofthe second coating layer covers a second surface area of the fertilizerpellet, wherein the first surface area is not same as the second surfacearea, an overlap layer, wherein the overlap layer covers a third surfacearea of the fertilizer pellet, wherein the third surface area isdifferent from the first surface area and the second surface area,wherein the overlap layer is formed by laminating the edge of the secondcoating layer with the edge of the first coating layer, wherein theoverlap layer is distinct from the first coating layer and the secondcoating layer; and the fertilizer pellet encapsulated in the firstcontinuous coating layer, the second continuous coating layer, and theoverlap layer is releasable through the first coating layer, the secondcoating layer, and the overlap layer over a period of time.

According to an embodiment herein, wherein the fertilizer includes anycommercially available fertilizer for use in agriculture cropsproduction.

According to an embodiment herein, wherein the first coating layerincludes any commercially available polymer film that can bethermoformed.

According to an embodiment herein, wherein the second coating layerincludes any commercially available polymer film that can bethermoformed.

A Polymer coated fertilizer comprising; a solid pellet of material thatincludes a fertilizer, the solid pellet of material having a surface, afirst coating layer covering a first surface of the fertilizer pellet, asecond coating layer covering a second surface of the fertilizer pellet,a third coating layer covering a third surface of the fertilizer pellet,wherein the second coating layer covers a surface not covered by thefirst coating layer, and wherein the third coating layer covers asurface not covered by the second coating layer; wherein the thirdcoating layer is visible as distinct from the first coating layer andthe second coating layer when viewed under a microscope, and fertilizerencapsulated between the first coating layer, the second coating layer,and the third coating layer is releasable through the first coatinglayer, the second coating layer, and the third coating layer over aperiod of time.

According to a preferred embodiment herein, a steps of manufacturingpolymer coated fertilizer comprising; placing plurality of fertilizerpellets 101 into a plurality of housing cavity, wherein the plurality ofhousing cavities are at a fixed distance from each other and house atleast one fertilizer pellet per cavity, applying a first continuouscoating layer 105 onto the first surface 101 a of the fertilizer pellet101, a vacuum pull is applied underneath the fertilizer pellet 101through an opening in the housing cavity, the vacuum suction pulls thefirst coating layer 105 around the fertilizer pellet 101 coating thefirst surface 101 a with the first coating layer 105 creating apartially coated fertilizer pellet 107 (FIG. 6 ) having a continuouscoating layer 105 and an edge 105 a covering the first surface 101 a ofthe fertilizer pellet 101, thereafter the partially coated fertilizerpellets 107 are turned over to expose the uncoated surface of thepartially coated fertilizer pellets. Thereafter, a second continuouscoating layer 108 is applied onto the partially coated fertilizerpellets 107, the second coating layer 108 is applied to coat the secondsurface 101 b of the fertilizer pellets 101, the second coating layer108 coats the second surface of the partially coated fertilizer pellets,and the edge 108 a of the second coating layer 108 goes over the edge105 a of the first coating layer 105 and melt fuses to create an overlaplayer 201, wherein the overlap layer comprises a part 105 a of the firstcoating layer 105 and a part 108 a of the second coating layer 108 a,bonded together to form a distinct layer, the edge of the second coatinglayer 108 a forms the top portion of the overlap layer 201 and the edge105 a of the first coating layer 105 forms the bottom part of theoverlap layer 201 (FIG. 7 ), the overlap layer runs along thecircumference of the fertilizer pellet 101 encircling the fertilizerpellet, the overlap layer 201 appears as a distinct layer either throughthe naked eye or when viewed under the microscope, and separates thefirst coating layer 105 and the second coating layer 108 on the surfaceof the fertilizer pellet 101, the fertilizer pellet encapsulated betweenthe first coating layer, the second coating layer, and the overlap layeris releasable through the first coating layer, the second coating layer,or the overlap layer.

According to an embodiment herein, As shown in FIG. 6 , a partiallycoated solid pellet 107 comprising; a solid pellet 101, a coating layer105 having a continuous structure and an edge 105 a; wherein the coatinglayer 105 covers a first surface area 101 a of the solid article 101 ina continuous layer; and a second surface area 101 b of the solid article101 is the uncoated surface area of the fertilizer pellet 101;

According to an embodiment therein, A partially coated pellet having apart 101 a of the surface area coated with a continuous coating layer105, wherein the coated surface area 101 a is less than 95% of the totalsurface area of the fertilizer pellet 101, a part of the surface area101 b of the solid pellet remains uncoated. The coating layer may beselected from a group of commercially available thermoplastic polymersor blends prepared from the commercially available thermoplasticpolymers such as water-soluble polymers, water insoluble polymers,biopolymers, natural polymers, biodegradable polymers, and syntheticpolymers,

The first continuous coating layer 105 and the second continuous layer108 may be same or different in terms of compositions, thickness, or anyother chemical property, whereas the overlap layer 201 is distinct fromthe first continuous coating layer and the second continuous coatinglayer.

According to an embodiment herein, the first coating layer 105 covers10% to 90% of the total surface area of the fertilizer pellet 101

According to an embodiment herein, the second coating layer 108 covers10% to 90% of the total surface area of the fertilizer pellet 101

According to an embodiment herein, the fertilizer pellets are appliedwith biologicals and thereafter coated with first and the second coatinglayer to encapsulate the biologicals in the coating layers, wherein thefirst and the second coating layers are made of low temperature meltingpolymers.

According to an embodiment herein, the first coating layer 105, and thesecond coating layer 108 may comprise; Polymers, plasticizers,micronutrients, fertilizers, fungicides, insecticides, herbicides,bio-acids, biologicals, or any plant growth promoter,

According to an embodiment herein, the overlap layer 201 may comprise anadhesive layer to help form a pinhole free overlap layer 201, theadhesive layer may be applied onto the edge 105 a and the said adhesivebinds the edge 105 a with the edge 108 a under heat or by curing.

According to an embodiment herein, a polymer coated urea tablet for usein agriculture production comprising; a urea fertilizer tablet, whereinthe weight of urea tablet is between 200 to 800 milligrams, a firstcontinuous film covering a first surface of the said urea tablet, asecond continuous film covering a second surface of the said ureatablet, and an overlap layer formed by heat sealing the edge of thefirst continuous film with the edge of the second continuous film, theoverlap layer formed is distinct from the first continuous film and thesecond continuous film, the overlap layer is visible as a distinct layerwhen viewed through a microscope, wherein the overlap has differentphysical or chemical properties than either the first or the secondcontinuous film; wherein the first continuous film and the secondcontinuous film may be made of the same polymer composition, wherein theoverlap layer has different physical and chemical properties than thefirst continuous film and the second continuous film. The diameter ofthe urea tablet is between 6 to 10 millimetres and thickness is between4 to 8 millimetres.

According to an embodiment herein, a system for coating a plurality ofarticles in a continuous process using a polymer melt is provided. Thesystem comprises a feeding mechanism connected to a first chill roll tosupply a plurality of articles. The first chill roll comprises aplurality of first cavities on a peripheral surface and the plurality offirst cavities houses and holds a plurality of articles. A first machineis provided for producing a first molten film and applying the firstmolten film on the plurality of articles held in the plurality of firstcavities in the first chill roll to partially coat the plurality ofarticles with the first molten film. A second chill roll is placed at aside of the first chill roll or the second chill roll is placed on abottom side of the first chill roll to receive a plurality of articlespartially coated with a first molten film. A second machine is providedfor producing and applying the second molten film on the plurality ofarticles held in the plurality of second cavities in the second chillroll and partially coated with the first molten film. A collectormechanism is provided to receive the plurality of articles coated withthe first molten film and the second molten film from the second chillroll.

According to an embodiment herein, a system for coating a plurality ofarticles in a continuous process using a polymer melt is provided. Thesystem comprises a first chill roll, a second chill roll, a firstmachine, a second machine, a feeding mechanism and a collectormechanism.

According to an embodiment herein, the first chill roll comprises aplurality of first cavities on a peripheral surface and the plurality offirst cavities houses and holds a plurality of articles.

According to an embodiment herein, the second chill roll is identical tothe first chill roll. The second chill roll is placed at a side of thefirst chill roll or the second chill roll is placed on a bottom side ofthe first chill roll. The second chill roll comprises a plurality ofsecond cavities on a peripheral surface. The plurality of secondcavities houses and holds a plurality of articles received from thefirst chill roll. The plurality of second cavities in the second chillroll matches with the plurality of first cavities in the first chillroll. The plurality of second cavities in the second chill roll and theplurality of first cavities in the first chill roll are arranged to faceeach other.

According to an embodiment herein, the system comprises a first machinefor producing a first molten film and applying the first molten film onthe plurality of articles held in the plurality of first cavities in thefirst chill roll to partially coat the plurality of articles with thefirst molten film. The first molten film has a desired thickness, widthand chemical properties. The first machine comprises a first polymerextruder and a first film molding die. The first polymer extruder mixes,melts and extrudes a polymer to generate a homogenous melt of polymer.The first film molding die is attached to an end of the first polymerextruder for receiving a molten feed from the first polymer extruder toproduce the first molten film of desired thickness and width. Thepolymer is a single polymer or a blend of polymers.

According to an embodiment herein, the system comprises a second machinefor producing a second molten film and applying the second molten filmon the plurality of articles held in the plurality of second cavities inthe second chill roll. The second molten film has a desired thickness,width and chemical properties. The second machine comprises a secondpolymer extruder and a second film molding die. The second polymerextruder mixes, melts and extrudes a polymer to generate a homogenousmelt of polymer. The second film molding die is attached to an end ofthe polymer extruder for receiving a molten feed from the second polymerextruder to produce the second molten film of desired thickness andwidth. The polymer is a single polymer or a blend of polymers.

According to an embodiment herein, the system comprises a feedingmechanism for feeding the plurality of articles to the first chill rolland a collection mechanism for collecting the plurality of articles fromthe second chill roll. The plurality of articles collected from thesecond chill roll are coated with the first polymer film at one side ofthe plurality of articles and with the second polymer film at anopposite side of the plurality of articles so that the plurality ofarticles are encapsulated within the first polymer film and the secondpolymer film. The plurality of articles is a controlled release article.

According to an embodiment herein, the plurality of articles is selectedfrom a group consisting of a fertilizer, a pharmaceutical tablet, adetergent tablet, a biocide tablet, a pesticide granule, an animal feedand a food particle. The plurality of articles is water soluble.

According to an embodiment herein, the plurality of articles is selectedfrom a group consisting of a polymer coated articles.

According to an embodiment herein, the mean article size is within therange of 1 mm to 150 mm.

According to an embodiment herein, the system further comprises acutting mechanism provided at the first chill roll and the second chillroll to cut the first polymer film and the second polymer film afterapplication on the plurality of articles. The cutting mechanism is asharp cutting edge provided on the surface of the first chill roll andthe second chill roll.

According to an embodiment herein, the system further comprises a rotarypin to push the plurality of articles held at the plurality of secondcavities in the second chill roll, when the second polymer film isapplied on the plurality of the articles coated partially with the firstpolymer film.

According to an embodiment herein, the first chill roll is rotated in aclockwise direction through a desired angle for receiving the pluralityof articles at the plurality of first cavities. The second chill roll isrotated in an anti-clockwise direction through a desired angle forreceiving the plurality of articles at the plurality of cavities. Thefirst chill roll and the second chill roll are rotated in a synchronizedmanner in the clockwise direction and in the anti-clockwise directionrespectively so that at least one of the plurality of first cavities inthe first chill roll is arranged opposite to at least one of theplurality of second cavities in the second chill roll to transfer theplurality of articles in the first cavities of the first chill roll tothe plurality of second cavities in the second chill roll.

According to an embodiment herein, the first chill roll and the secondchill roll comprise an internal fluid circulation mechanism forcirculating a fluid to control a surface temperature of the first chillroll. The first chill roll and the second chill roll comprise anon-stick coating on an outer surface to avoid a sticking of the moltenfilm. The first chill roll and the second chill roll are rotatablecylindrical drums.

According to an embodiment herein, each of the plurality of firstcavities and each of the plurality of second cavities hold one article.The plurality of first cavities and the pluralities of the secondcavities are arranged in a shape selected from a group consisting of atablet, spike, circular, rectangular, square and hexagonal shapes. Eachone of the plurality of first cavities and each one of the plurality ofsecond cavities holds at-least one article by a vacuum. The plurality offirst cavities and the plurality of second cavities comprise an openingor hole in a bottom to provide the vacuum for holding the plurality ofarticles. A size of the plurality of first cavities is larger than asize of the plurality of articles and a size of the plurality of secondcavities is larger than a size of the plurality of articles. Theplurality of first cavities and the plurality of second cavitiescomprise a compressable cushion ring in a bottom. The compressiblecushion ring is made up of a material selected from a group consistingof a soft rubber material or a rubber like material.

According to an embodiment herein, the first polymer film die and thesecond polymer film die is any one of a curtain coating and a slot dye.The first polymer film die and the second polymer film die produce asingle layer polymer film or a multilayer polymer film.

According to an embodiment herein, the polymer is melt processed into amolten film of desired thickness.

According to an embodiment herein, the first polymer film is coated onthe surface of the plurality of articles in a range of 1%-991%. Thesecond polymer film is coated on the surface of the plurality ofarticles coated partially with the first polymer film in a range of1%-99%.

According to an embodiment herein, the first polymer film and the secondpolymer film comprise one or more additives. The one or more additivesare selected from a group consisting of synthetic or natural hydrophilicadditives, surfactants, inorganic minerals, biodegradable additives,pigments and water soluble additive. The hydrophilic additives andsurfactants are added for increasing a moisture permeability of thefirst polymer film and the second polymer film.

According to an embodiment herein, the inorganic mineral is selectedfrom a group consisting of talc, calcium carbonate, mica, silica andtheir derivatives. The inorganic minerals are added for modifying amoisture permeability, reducing a temperature induced expansion of thefirst polymer film and the second polymer film, and reducing a tackinessof the first polymer film and the second polymer film, and preventing acaking or agglomeration of the plurality of articles coated with thefirst polymer film and the second polymer film.

According to an embodiment herein, wherein the biodegradable additivesare added for adding a biodegradable characteristics to the firstpolymer film and the second polymer film and for expediting abiodegradation of the first polymer film and the second polymer film.The additives are added to the first polymer film and the second polymerfilm layer in a range of 0.01%-50% of a combined dry weight of the firstpolymer film and the second polymer film.

According to an embodiment herein, the desired thickness of the firstpolymer film and the second polymer film is within a range of 5 micronsto 300 microns. The desired temperature of the first molten polymer filmand the second molten polymer film is within a range of 50° C. to 500°C. The desired chemical property of the first polymer film and thesecond polymer film is water vapor transmission rate (WVTR). The WVTRvalue of the first polymer film and the second polymer film is within arange of 0.01 g/(m²·day) to 20,000 g/(m²·day).

According to an embodiment herein, a method is provided for coating aplurality of articles in a continuous process using a polymer. Themethod comprises extruding and applying a first coating layer with afirst molten polymer film on a plurality of articles held on a pluralityof first cavities in a first chill roll for generating a plurality ofarticles coated partially with the first polymer film. The plurality ofarticles coated partially with the first polymer film is transferredfrom the first chill roll to a second chill roll. An uncoated portion ofthe plurality of articles coated partially with the first polymer filmis exposed. A second coating layer of a second molten polymer film isextruded and applied on the plurality of articles held on a plurality ofsecond cavities in the second chill roll for generating a plurality ofarticles fully coated with the first polymer film and the second polymerfilm. The plurality of articles is encapsulated between the firstcoating layer and the second coating layer by sealing the first polymerfilm and the second polymer film coated on the plurality of articles bymelt fusing the second polymer film with the first polymer film on anoverlapping area of the first polymer film and the second polymer film.The encapsulated plurality of articles is released over a time period bya diffusion of the encapsulated plurality of articles through the firstpolymer film or the second polymer film.

According to an embodiment herein, the plurality of articles are held inthe plurality of first cavities and in the plurality of second cavitiesby a vacuum suction adopted at a bottom of the plurality of firstcavities and at the plurality of second cavities. A pulling force of thevacuum suction under the plurality of articles is adapted to pull thefirst polymer film and the second polymer film around the plurality ofarticles and to adhere the first polymer film and the second polymerfilm respectively to an opposing surface of the plurality of articles.

According to an embodiment herein, the first polymer film is coated onthe surface of the plurality of articles in a range of 1%-99%. Thesecond polymer film is coated on the surface of the plurality ofarticles coated partially with the first polymer film in a range of1%-99%.

According to an embodiment herein, the polymer is melt processed into amolten film.

According to an embodiment herein, the first polymer film and the secondpolymer film comprises one or more additives. The one or more additivesare selected from a group consisting of hydrophilic additives,surfactants, inorganic minerals, biodegradable additives, pigments andwater soluble additive. The hydrophilic additives or surfactants areadded for increasing a moisture permeability of the first polymer filmand the second polymer film.

According to an embodiment herein, the inorganic mineral is selectedfrom a group consisting of talc, calcium carbonate, mica, silica andtheir derivatives. The inorganic minerals are added for reducing amoisture permeability, reducing a temperature induced expansion of thefirst polymer film and the second polymer film, and reducing a tackinessof the first polymer film and the second polymer film to prevent acaking of the plurality of articles coated with the first polymer filmand the second polymer film.

According to an embodiment herein, the biodegradable additives are addedfor adding a biodegradable characteristic to the first polymer film andthe second polymer film and for expediting a biodegradation of the firstpolymer film and the second polymer film.

According to an embodiment herein, the additives are added to the firstpolymer film and the second polymer film layer in a range of 0.0%-50% ofa combined dry weight of the first polymer film and the second polymerfilm.

According to an embodiment herein, the desired thickness of the firstpolymer film and the second polymer film is within a range of 5 micronsto 300 microns. The desired temperature of the first polymer film andthe second polymer film is within a range of 50° C. to 500° C. Thedesired chemical property of the first polymer film and the secondpolymer film is water vapor transmission rate (WVTR). The WVTR value ofthe first polymer film and the second polymer film is within a range of0.01 g/(m²·day) to 20,000 g/(m²·day).

According to an embodiment herein, the first chill roll and the secondchill roll are rotatable cylindrical drums.

According to an embodiment herein, a method for manufacturing acontrolled release fertilizer involves placing the fertilizer granulesonto a surface and applying a first layer of polymer onto the exposedsurface of the fertilizer granule. Then the uncoated portion offertilizer is exposed and a second layer of polymer is applied toencapsulate the fertilizer granule between the first polymer layer andthe second polymer layer such that the fertilizer granules arereleasable over a time by a diffusion through at least one of the firstpolymer film or the second polymer film.

According to one embodiment herein, the manufacturing process ofpolymer-coated fertilizers has two main steps. In the first step, thefertilizer granules are partially coated by a first polymer film.Thereafter a second polymer film is applied onto the remaining uncoatedfertilizer granule surface thereby encapsulating the fertilizer betweenthe two polymer films.

According to one embodiment herein, an apparatus for coating pluralityof articles in a continuous process using polymer melt comprises a firstchill roll, a second identical chill roll, a first machine, a secondmachine, a feeding mechanism and a collection mechanism. The first chillroll comprises a plurality of cavities placed side by side and on theperiphery of the first chill roll. The cavities are capable of holdingthe articles. The second identical chill roll comprises plurality ofcavities placed side by side and on the periphery of second chill rolland the cavities of first and second chill rolls are facing each other.The first machine is used for producing a molten film of desiredthickness, width and properties. The first polymer film is placed insuch a way that the molten polymer film is applied directly onto thearticles held in the cavity of the first chill roll. The second machineis adapted for producing a molten film of desired thickness, width andproperty. The second machine is placed in such a way that the moltenfilm is applied directly onto the articles held in the cavity of thesecond chill roll. The feeding mechanism is for feeding the articlesonto the first chill roll. The collection mechanism is for collectingcoated articles from the second chill roll.

According to one embodiment herein, the chill roll is a cylindrical drumcapable of rotating. The chill roll has a plurality of cavities on thecircumferential surface of the roll. The chill roll has an internalfluid circulation to control a surface temperature of the chill roll.The chill roll has a non stick coating applied on the surface of theroll. The chill roll rotates in a synchronized way so that cavities onthe surface of the first chill roll always face the identical cavitieson the second chill roll.

The cavity of the chill roll is of any shape and dimension. The cavityof the chill roll is suitable for holding the articles being coated. Theshape of the cavity is chosen from a tablet, spike, circular,rectangular, square or hexagonal shape. The cavities are distributed allover the circumference of the first and second chill roll. Further thecavities are of larger dimension than that of the articles being coated.The cavities have soft rubber or rubber like compressable cushion ringsin the bottom. The cavity has an opening/hole in the bottom throughwhich a vacuum suction is provided to hold the articles. Further thearticles are housed in the cavity and held with the vacuum suction inthe cavity. Only one article is housed per cavity.

According to one embodiment herein, the first and second machine usedfor producing a molten film comprises a polymer extruder and a film die.The polymer extruder is capable of mixing, melting and extruding anycommercially available polymer or blend of polymers or additives andcreating a homogenous melt. The polymer film die is capable of producinga molten film of desired thickness width and properties from the polymerfilm melt produced by the extruder. The die is attached to the end ofthe extruder.

According to one embodiment herein, the film die is a curtain coatingdie or slot die capable of producing a polymer film using polymer melt.The film die has a single layer or multilayer polymer film extrusioncapability. The film die is a commercially available extrusion diecapable of producing a molten polymer film of desired thickness, widthand properties.

According to one embodiment herein, the method for coating thefertilizers is initiated by feeding the articles on the first chill rollwhere the articles are held in the cavities by the vacuum suction at thebottom of the cavity. The next step is extruding a first layer of moltenpolymer film on the articles. The pull of vacuum suction under the saidarticles pulls the molten polymer layer around the articles to adherethe molten film to the surface of the article to create a partiallycoated article. Further the partially coated articles are transferred tothe cavity of the second chill roll and the uncoated portion of thepartially coated particles is exposed. A second layer of molten polymeris extruded and applied on the uncoated portion of the partially coatedarticles in such a way that second coating layer overlaps the firstcoating layer and the high temperature of the molten second layer helpsin laminating the second layer with the overlapping area of the firstlayer. Hence the fertilizer particle or an article is sealed orencapsulated between the first polymer layer and second polymer layer.

According to one embodiment herein, the articles are any commerciallyavailable fertilizer granule in any dimension and shape. Further thearticles is any one selected from a group consisting of a detergenttablet of any shape and dimension, a biocide tablet of any shape anddimension, a pesticide granule of any shape and dimension, an animalfeed of any shape and dimension, and a food particle of any shape anddimension. The articles have even or uneven shape. The articles chosenare water soluble.

According to one embodiment herein, the first and second polymer film isany extrusion grade polymer, capable of producing a film of desiredthickness and properties. The desired temperature of the first polymerfilm and the second polymer film is within a range of 50° C. to 500° C.Further the thickness of the polymer film is in the range of 5-300micron. The desired chemical property of the first polymer film and thesecond polymer film is water vapor transmission rate (WVTR). The WVTRvalue of the first polymer film and the second polymer film is within arange of 0.01 g/(m²·day) to 20,000 g/(m²·day).

According to one embodiment herein, the partially coated articles havethe polymer coat covering in the range of 1%-99% of the surface area.Further the second polymer film coating on the partially coated articleshave polymer coat covering in the range of 1%-99% of the surface area,of the partially coated article.

According to one embodiment herein, a method of producing the controlledrelease delivery systems comprises coating a first layer of polymer ontothe surface of the article creating partially coated articles. Theremaining uncoated portion of the surface area is exposed and appliedwith a second coating layer. The article is sealed between the firstcoating layer and the second coating layer by melt fusing the secondcoating layer with the first coating layer in the overlapping area ofthe first coating layer and the second coating layer. The article isencapsulated between the first coating layer and the second coatinglayer. The encapsulated article between the first coating layer andsecond coating layer is releasable over the time by diffusion throughthe first coating layer or the second polymer film.

According to one embodiment herein, the first polymer film and secondpolymer film have multiple film layers forming a single laminatedcoating layer. The first or second polymer films have additives into thefilm structure. The additives are selected from the group consisting ofhydrophilic additives, inorganic minerals, biodegradable additives andpigments. The hydrophilic additives are added for increasing themoisture permeability of the coating layer. Inorganic minerals such astalc, calcium carbonate, mica or silica or their derivatives are addedfor reducing moisture permeability, reducing a temperature inducedexpansion of the polymer coating and reducing a tackiness of the coatingto prevent a caking of the coated articles. The biodegradation additivesare added for expediting the biodegradation of the coating layer. Thepigments are added for providing a color to the coating films. Theamount of additives added to the polymer layer is within a range of0.01%-50% of the combined dry weight of the first or second coatinglayer.

According to one embodiment herein, the first or second polymer film hasmultiple film layers laminated to form a single coating layer. Furtherthe multilayer coated films are of different thickness or differentadditives or have additive loading levels.

According to one embodiment herein, cheap polymers are used to coat thefertilizer granules. Further the dry fertilizer granules in any shape,form are coated, thereby eliminating the energy cost of granulating thefertilizer. The method of coating the fertilizer granules does notinvolve any solvent or catalyst. The method gives a uniform coating onthe fertilizer granules. Furthermore the method allows an application ofmultiple polymers simultaneously thereby allowing the manufacturer toproduce a fertilizer coated with multiple polymer layers. The method hasability to apply a coating film with desired weight in a single timethereby saving time, space and energy to produce coated products.

FIG. 1 illustrates a block diagram of a system for manufacturing thepolymer coated fertilizers, according to an embodiment herein. Withrespect to FIG. 1 , the fertilizer granule 100 is fed onto the cavity102 a of the first chill roll 103 a. The fertilizer granule 101 is heldinto the first cavity 102 a of the first chill roll 103 a with a vacuumsuction 104 a through the tiny pores in the cavity 102 a. Thereafter thefirst polymer film 105 from the first polymer extruder 106 a is appliedonto the fertilizer granule 101 held in a grid like pattern in thecavity 102 a on the chill roll 103 a. This creates a partially coatedfertilizer 107. The partially coated fertilizer 107 is then transferredto the second chill roll 103 b where this partially coated fertilizer107 is held into the second cavity 102 b by the vacuum suction 104 b.The first cavity 102 a of the first chill roll 103 a is aligned in sucha way that the cavity 102 a of the chill roll 103 a is facing the cavity102 b of the chill roll 103 b while transferring the partially coatedfertilizer 107. The transfer of the partially coated fertilizers 107from the first chill roll 103 a to second chill roll 103 b exposes theuncoated part of the partially coated fertilizer 107. Thereafter thesecond polymer film 108 is extruded from the second polymer extruder 106b and this second polymer layer 108 is then coated onto the uncoatedportion of partially coated fertilizer 107 encapsulating the fertilizergranules between the first polymer film 105 and the second polymer film108. The second polymer film 108 coats and seals the coating by meltingand fusing with first polymer film 105 thereby producing the polymercoated fertilizer 109. Thereafter these coated fertilizers 109 are sentto collection bin 110 for packaging.

According to one embodiment herein, the first chill roll 103 a and thesecond chill roll 103 b is replaced with a perforated steel belt withvacuum.

According to one embodiment herein, the cavity 102 a is made ofelectrically conductive metal while the first chill roll 103 a and thesecond chill roll 103 b have a coating of electrically neutral material.According to one embodiment herein, the charged fertilizer granule areattracted towards the cavity 102 a and the fertilize granules 101 areheld in its place without the use of vacuum suction 104 a, whenelectrically charged fertilizer granules 101 are fed onto the chill roll103 a.

According to one embodiment herein, the extruder 106 a or extruder 106 bhave co-extrusion facility with an ability to extrude multiple layers ofpolymers.

According to one embodiment herein the extruders 106 a and 106 b arereplaced with a suitable coating devices such as, but not limited to,spray coating, curtain coating, powder coating, rod coating, thermallamination coating, or UV lamination coating devices.

According to one embodiment herein, the fertilizer granule 101 is anyone of rectangular, tablet, hemispherical, split pea, spike, shapes orany shape in which the fertilizers are available commercially.

According to one embodiment herein, the cavity 101 is rectangular,tablet, square, hemispherical, spike, or such shapes.

FIG. 2 illustrates a schematic view of a partially coated fertilizergranules obtained from a first chill roll in the system formanufacturing the polymer coated fertilizers, according to an embodimentherein. With respect to FIG. 2 the fertilizer granule 101 is partiallycoated with the first polymer film 105 to obtain a partially coatedfertilizer granule 107.

FIG. 3 illustrates a schematic view of the full coated fertilizergranules, obtained from a second chill roll in the system formanufacturing the polymer coated fertilizers, according to an embodimentherein. With respect to FIG. 3 the full polymer-coated fertilizergranule 109 has the fertilizer granule 101 coated with the first polymerfilm 105 and the second polymer film 108 on the two opposite faces ofthe fertilizer granule so that the fertilizer granule is encapsulatedbetween the first polymer film 105 and the second polymer film 108.

FIG. 4 illustrates a schematic view of a first machine for applying afirst polymer film and the polymer film breaking mechanism in the systemfor manufacturing the polymer coated fertilizers, according to anembodiment herein. With respect to FIG. 4 , the chill roll surfaces havedesigns to assist the breakage of the film 105 while applied onto thefertilizer granule 101 from the extruder 106 a. The design include butnot limited to a sharp edge 111 a, around the cavity that tears the filmaway while the film is being pulled under vacuum suction 104 a aroundthe fertilizer granule 101.

FIG. 5 illustrates a schematic view of a second machine for applying asecond polymer film with the polymer film cutting mechanism and a rotarypin for pushing the fertilizer granules through the cavity in the systemfor manufacturing the polymer coated fertilizers, according to anembodiment herein. With respect to FIG. 5 , a rotary pin 112 is providedfor pushing the fertilizer granules through the cavity. The chill rolls103 b has a rotary pin 112 aligned under the cavity 102 b of thecylinder in such a way that the pins 112 push the partially coatedfertilizer 107 up towards the polymer layer 108 right at the moment whenthe polymer layer 108 is being applied from the extruder 106 b. Thevacuum suction 104 b is deployed to hold the partially coated fertilizergranule 107. The partially coated fertilizer granule 107 is held by thechill rolls 103 b by vacuum suction 104 b. The extruder 106 b gives thesecond molten polymer film 108, to coat the partially coated fertilizergranule 107. The surface of the chill rolls 103 b has sharp edge 111 bto assist the breakage of the polymer film while applied onto thefertilizer granule 107. The design include but not limited to a sharpedge 111 b, around the cavity that tears the film away while the film isbeing pulled under vacuum suction 104 b around the fertilizer granule107.

FIG. 6 illustrates a schematic view of a partially coated fertilizerpellet 107 obtained after the application of the first coating layer 105for manufacturing the polymer coated fertilizers, according to anembodiment herein. With respect to FIG. 6 the first surface area 101 aof the fertilizer granule 101 is coated with the first coating layer 105having a continuous structure and an edge 105 a to obtain a partiallycoated fertilizer pellet 107.

FIG. 7 illustrates a schematic view of the completely coated orencapsulated fertilizer pellet, obtained after the application of thesecond coating layer for manufacturing the polymer coated fertilizers,according to an embodiment herein. With respect to FIG. 7 theencapsulated fertilizer pellet 109 has the fertilizer pellet 101 coatedwith the first polymer film 105 covering the first surface area 101 a ofthe fertilizer pellet 101, the second coating layer 108 covering thesecond surface area 101 b of the fertilizer pellet 101, and an overlaplayer formed by sealing the edge 105 a of the first coating layer 105with edge 108 a of the second coating layer 108 on the surface of thefertilizer pellet 101. As illustrated in FIG. 7 , the overlap layer runsalong the circumference of the fertilizer pellet 101 encircling thefertilizer pellet, and the first coating layer and the second coatinglayer are on the opposite side of the overlap layer, the two oppositecoating surfaces joined by the overlap layer completely encapsulate thefertilizer pellet 101 between the first coating layer 105 and the secondcoating layer 108 and the overlap layer 201.

FIG. 8 illustrates another schematic view of the completely coatedfertilizer pellet, obtained after the application of the second coatinglayer for manufacturing the polymer coated pellet, according to anembodiment herein. As presented in FIG. 8 there are three layerscovering three different parts of the surface of the fertilizer pellet;first coating layer 105 covers a first surface of the fertilizer pellet,101 a second coating layer 108 covers a second surface of the fertilizerpellet 101, and overlap layer 201 covering a third surface of thefertilizer pellet 101. The overlap layer 201 comprises; a part of thefirst coating layer 105 and a part of the second coating layer 108 fusedor laminated together to form a composite layer, wherein the overlaplayer 201 is distinct from the first coating layer 105 and the secondcoating layer 108 and is visible as a distinct layer when seen through amicroscope.

According to one embodiment herein, the steel belt is used to eliminatethe use of first chill roll. In yet another embodiment of the inventiona series of soft cushion protective rollers can be used on the surfaceof the chill roll gently pressing the granules onto the cylinder so thatthe granules do not fly off due to a centrifugal force of the rotatingchill roll. Alternatively an air cushion is used to generate air jets orelectrostatic charge on the granules to prevent a flying off of thegranules from the rotating chill roll.

According to one embodiment herein, the layer of polymer containsvarious types of additives to enhance the properties of polymer such asfertilizer release rate through the polymer layer, biodegradation of thepolymer layer, UV resistance of the polymer layer, resistance oftemperature induced fertilizer release through the layer using talc andother minerals.

According to one embodiment herein, the surface of the coated granulescomprises of water absorption chemicals such as superabsorbent.

According to one embodiment herein, the surface of the chemicalscontains paper particles or cellulose particles attached to the surfaceof the coated granules. These cellulose particles are used to carrypesticides by absorbing the pesticides onto the cellulose particlesattached to the coated surface.

According to one embodiment herein, the polymer film comprises of manypolymer layers co-extruded as a single layer of polymer.

The foregoing description of the specific embodiments will so fullyreveal the general nature of the embodiments herein that others can, byapplying current knowledge, readily modify and/or adapt for variousapplications such specific embodiments without departing from thegeneric concept, and, therefore, such adaptations and modificationsshould and are intended to be comprehended within the meaning and rangeof equivalents of the disclosed embodiments. It is to be understood thatthe phraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Therefore, while the embodimentsherein have been described in terms of preferred embodiments, thoseskilled in the art will recognize that the embodiments herein can bepracticed with modification within the spirit and scope of the appendedclaims.

Although the embodiments herein are described with various specificembodiments, it will be obvious for a person skilled in the art topractice the invention with modifications. However, all suchmodifications are deemed to be within the scope of the claims. It isalso to be understood that the following claims are intended to coverall of the generic and specific features of the embodiments describedherein and all the statements of the scope of the embodiments which as amatter of language fall there between.

1.-20. (canceled)
 21. A method of manufacturing a polymer coatedfertilizer, the method comprising: placing a solid substrate in a firstcavity; applying a first coating layer onto a first exposed surface areaof the solid substrate, the first coating layer covering a part of thefirst exposed surface area to create a partially coated solid substrate;transferring the partially coated solid substrate into a second cavityin such a way that exposes a second exposed surface area of thepartially coated substrate; applying a second coating layer onto thesecond exposed surface area of the partially coated substrate in such away that the second coating layer covers the second exposed surface areaand forms a sealing layer with the first coating layer to form thepolymer coated fertilizer; wherein the polymer coated fertilizerreleases the solid substrate through at least one of the first coatinglayer and the second coating layer over a period of time when placed inan agriculture media.
 22. The method of claim 21, wherein the fertilizerincludes at least one of the following: an organic fertilizer, aninorganic fertilizer, a natural fertilizer, a synthetic fertilizer, amicronutrient, an insecticide, a fungicide, a herbicide, a nitrificationinhibitor, a bioinoculant, a urease inhibitor, and an aluminum sulfate.23. The method of claim 21, wherein the solid substrate includes atleast one of the following: a tablet, a capsule, a briquette, and agranule.
 24. The method of claim 21, wherein the first coating layerincludes at least one of the following: a natural polymer, a syntheticpolymer, a biodegradable polymer, a non-biodegradable polymer, aprocessing additive, a polymer stabilizing additive, an inorganicmineral, a biodegradation additive, a oxo-biodegradation additive, anitrification inhibitor, a urease inhibitor, a hydrogel particle, anorganic surfactant, an inorganic surfactant, a pigment, a chemicaltaggant, a physical taggant, a herbicide, an insecticide and afungicide.
 25. The method of claim 21, wherein the second coating layerincludes at least one of the following: a natural polymer, a syntheticpolymer, a biodegradable polymer, a non-biodegradable polymer, a polymerprocessing additive, a polymer stabilizing additive, an inorganicmineral, a biodegradation additive, a oxo-biodegradation additive, anitrification inhibitor, a urease inhibitor, a hydrogel particle, anorganic surfactant, an inorganic surfactant, a pigment, a chemicaltaggant, a physical taggant, a herbicide, an insecticide and afungicide.
 26. The method of claim 21, wherein at least one of the firstcoating layer and the second coating layer includes any film extrusiongrade polymer of natural or synthetic origin.
 27. The method of claim21, wherein at least one of the first coating layer and the secondcoating layer has a water vapor transmission rate within the range of 1g/(m²·day) to 2000 g/(m²·day).
 28. The method of claim 21, wherein atleast one of the first coating layer and the second coating layer ismade up of multiple coating layers.
 29. The method of claim 21, whereinthe first coating layer and the second coating layer have a samethickness, and the sealing layer has a greater thickness than the samethickness of the first coating layer and the second coating layer. 30.The method of claim 21, wherein the first coating layer, the secondcoating layer, and the sealing layer each have a different thickness.31. The method of claim 21, wherein the solid substrate has a diameterwithin a range of 2 mm to 150 mm.
 32. The method of claim 21, whereinthe solid substrate is a urea tablet having a weight within a range of100 mg to 800 mg.
 33. The method of claim 21, wherein the sealing layeris formed by laminating an edge of the second coating layer with an edgeof the first coating layer, wherein the sealing layer is distinct fromthe first coating layer and the second coating layer.
 34. The method ofclaim 21, wherein the solid substrate includes any fertilizer for use inagriculture crops production.
 35. The method of claim 21, wherein thefirst coating layer includes any polymer film that can be thermoformed.36. The method of claim 21, wherein the second coating layer includesany polymer film that can be thermoformed.
 37. The method of claim 21,wherein applying the first coating layer onto the first exposed surfacearea of the solid substrate includes depositing the first coating layeronto the first exposed surface area of the solid substrate under apulling force.
 38. The method of claim 21, wherein the first coatinglayer is deposited onto the first exposed surface area of the solidsubstrate includes depositing the first coating layer onto the firstexposed surface area of the solid substrate under a first pulling forcecausing the first coating layer to wrap around the solid substratebefore the second coating layer is deposited under a second pullingforce so that an edge of the first coating layer is interior to an edgeof the second coating layer in the sealing layer.
 39. The method ofclaim 38, wherein the edge of the first coating layer is wholly interiorto the edge of the second coating layer in the overlap layer.